<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	  <style>
		    html{
					font-size: 20px;	
				}
				body{
					font-size: 30px;
				}
				div{
					font-size: 40px;					
				}
				span{
					font-size: 1.5em;
				}
		</style>	
	</head>
	<body>
	   
		 <div><span>ABCD</span></div>
	
	</body>
</html>
